JP7390237B2 - Anisotropically conductive resin composition, anisotropically conductive adhesive film, and micro LED display device - Google Patents

Description

The present invention relates to an anisotropically conductive resin composition, an anisotropically conductive adhesive film, and a micro LED display device.

BACKGROUND ART In recent years, so-called micro-LEDs using small LEDs (Light Emitting Diodes) have been attracting attention as a display element following liquid crystal display elements and organic electroluminescent elements. Like organic electroluminescent elements, micro LEDs are light emitting elements, and active matrix display devices using such light emitting elements are known (Patent Document 1 and Patent Document 2).
In addition, conventionally, as a method of mounting a drive circuit on a display element, display is carried out via an anisotropic conductive film (ACF) (hereinafter sometimes referred to as "anisotropic conductive adhesive"). Electrical connection between an extraction electrode portion of an element and a connection terminal on a drive circuit board has been carried out (Patent Document 3).

WO2019/220267 publication Japanese Patent Application Publication No. 2007-123861 Japanese Patent Application Publication No. 2010-192802

However, when mounting small LED chips used in micro LEDs or repairing them, alignment marks for positioning may be checked. For example, when mounting a small LED chip on a mounting board using an anisotropic conductive adhesive, in order to accurately mount a small LED chip at a predetermined position on the mounting board, a positioning mark is formed on the mounting board. It is necessary to recognize the alignment mark using a camera or the like including an image sensor. In such cases, in order to avoid recognition errors, an anisotropically conductive adhesive made of an anisotropically conductive resin composition that has high optical transparency and excellent discoloration resistance may be required.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide an anisotropically conductive resin composition having excellent light transmittance.

As a result of extensive studies to solve the above problems, the present inventors have discovered an anisotropic conductive resin composition containing a silicone-modified epoxy resin having a specific structure, a curing agent, conductive particles, and a specific fluoropolymer. For example, electrical connections between electrodes, etc. on a substrate having a display element, etc. and connection terminals, etc. of a drive circuit board, or electrical connections when mounting a small LED chip, etc., can be easily and precisely performed. The present invention was completed by discovering that a cured product suitable for adhesives can be obtained.
That is, the present invention provides the following (1) to (7).
(1) An anisotropic conductive resin composition comprising (A) a silicone-modified epoxy resin, (B) a curing agent, (C) conductive particles, and (D) a fluorine-containing polymer, (A) An anisotropically conductive resin composition in which a silicone-modified epoxy resin has a structure represented by the following general formula (1).

[In formula (1), R ¹ each independently represents a monovalent organic group, R ² each independently represents a chain aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms. It represents a group selected from an aliphatic hydrocarbon group and a phenyl group, and Y represents an organic group containing a cyclic ether group. X may be the same or different. a and b are positive numbers, a+b=1 and 0.3≦a<1, and n is 1 to 25. ]
(2) The fluoropolymer (D) comprises a polymerized unit (a) based on a fluoroolefin, a polymerized unit (b) based on an alkyl vinyl ether, and/or a polymerized unit (c) based on a carboxylic acid vinyl ester. The anisotropically conductive resin composition according to (1) above, which is a fluorine-containing copolymer.
(3) The fluorine-containing polymer (D) contains CTFE (chlorotrifluoroethylene), hydroxybutyl vinyl ether, and a monomer copolymerizable with the CTFE and the hydroxybutyl vinyl ether. ) or the anisotropically conductive resin composition according to (2). (4) The copolymerizable monomer is at least one selected from α-olefins, haloolefins, allyl carboxylates, allyl ethers, and (meth)acrylic esters ( 3) The anisotropically conductive resin composition according to item 3).
(5) The anisotropic conductive resin composition according to any one of (1) to (4) above, wherein the conductive particles (C) have an average particle size of 0.5 to 10 μm.
(6) An anisotropically conductive adhesive film formed by forming the anisotropically conductive resin composition according to any one of (1) to (5) above into a sheet shape.
(7) A micro LED display device in which micro LEDs are arranged and mounted in an array on a substrate using the anisotropically conductive adhesive film described in (6) above.

According to the present invention, it is possible to provide an anisotropically conductive resin composition with excellent light transmittance.

[Anisotropic conductive resin composition]
An anisotropically conductive resin composition comprising (A) a silicone-modified epoxy resin, (B) a curing agent, (C) conductive particles, and (D) a fluorine-containing polymer, the composition comprising: An anisotropically conductive resin composition in which a silicone-modified epoxy resin has a structure represented by the following general formula (1).

[In formula (1), R ¹ each independently represents a monovalent organic group, R ² each independently represents a chain aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms. It represents a group selected from an aliphatic hydrocarbon group and a phenyl group, and Y represents an organic group containing a cyclic ether group. X may be the same or different. a and b are positive numbers, a+b=1 and 0.3≦a<1, and n is 1 to 25. ]

[(A) Silicone modified epoxy resin]
The anisotropically conductive resin composition of the present invention contains as an essential component a silicone-modified epoxy resin having a structure represented by the following general formula (1).

In formula (1), R ¹ each independently represents a monovalent organic group, R ² each independently represents a chain aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a cyclic aliphatic group having 3 to 10 carbon atoms. Y represents a group selected from group hydrocarbon groups and phenyl groups, and Y represents an organic group containing a cyclic ether group. X may be the same or different. a and b are positive numbers, a+b=1 and 0.3≦a<1, and n is 1 to 25.
Examples of the monovalent organic group for R ¹ include a monovalent organic group having a hydroxy group, a linear or branched alkyl group, an alkoxy group, and an aryl group.
Examples of the chain aliphatic hydrocarbon group having 1 to 10 carbon atoms for R ² include a methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, and n-hexyl group.
Examples of the cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms for R ² include a cyclopropyl group, a cycloptyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.
Examples of the organic group containing a cyclic ether group in Y include cyclic ether groups having a 3- to 6-membered ring structure, particularly 3- or 4-membered cyclic ether groups with large ring strain energy and high reactivity. is preferable, and a three-membered ring ether group is more preferable. Glycidoxyalkyl group in which an oxyglycidyl group is bonded to an alkyl group having 1 to 3 carbon atoms such as β-glycidoxyethyl group, γ-glycidoxypropyl group, β-(3,4-epoxycyclohexyl)ethyl group , an alkyl group having 3 or less carbon atoms substituted with a cycloalkyl group having 5 to 8 carbon atoms and having an oxirane group is preferable.

In this embodiment, the silicone-modified epoxy resin is preferably 30 to 80 parts by mass, more preferably 40 to 70 parts by mass, and 45 to 80 parts by mass, more preferably 40 to 70 parts by mass, based on 100 parts by mass of the anisotropically conductive resin composition. More preferably, the amount is 60 parts by mass.
When the mass part of the silicone-modified epoxy resin is within this range, it will tend to have heat resistance, light resistance, and migration resistance.
Note that the silicone-modified epoxy resin is described, for example, in JP-A No. 2012-241136.

[(B) Curing agent]
The anisotropically conductive resin composition of the present invention contains (B) a curing agent as an essential component.
As the curing agent (B), since the silicone-modified epoxy resin (A) has an epoxy group, examples of the curing agent include commonly used amine curing agents and acid anhydride curing agents in thermal curing. Among these, it is preferable to use an acid anhydride curing agent from the viewpoint of light transmittance, heat resistance, etc.
Examples of acid anhydride curing agents include succinic anhydride, phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl- Hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl-tetrahydrophthalic anhydride, nadic anhydride, methyl nadic anhydride, norbornane-2,3-dicarboxylic anhydride, methylnorbornane-2,3-dicarboxylic anhydride and methyl Examples include cyclohexenedicarboxylic anhydride. Among these, 4-methyl-hexahydrophthalic anhydride, tetrahydrophthalic anhydride, nadic anhydride, or methylcyclohexenedicarboxylic anhydride is preferred from the viewpoint of light transparency.
These can be used alone or in combination of two or more.

In this embodiment, the curing agent is preferably used in an amount of 4 to 70 parts by mass based on 100 parts by mass of the total mass of the anisotropically conductive resin composition, from the viewpoint of obtaining good curability and properties of the cured product. , more preferably 10 to 50 parts by weight, and even more preferably 15 to 35 parts by weight.

Furthermore, a curing accelerator and a curing catalyst that are effective in reacting with the curing agent can be used in combination.
Examples of the curing accelerator include organic phosphorus compounds such as triphenylphosphine and tributylphosphine; ethyltriphenylphosphonium bromide, methyltriphenylphosphonium diethyl phosphate, and tetra-n-butylphosphonium-O,O'-diethyl. Quaternary phosphonium salts such as phosphorodithionate; 1,8-diazabicyclo(5,4,0)undecane-7-ene, 1,8-diazabicyclo(5,4,0)undecane-7-ene and octylic acid Examples include quaternary ammonium salts such as zinc octylate, tetrabutylammonium bromide, and the like. Among these, from the viewpoint of adhesion, tetra-n-butylphosphonium-O,O'-diethylphosphorodithionate and 4hydroxy 2(triphenylphosphonium)phenolate are preferred.
These can be used alone or in combination of two or more.

Examples of the curing catalyst include organic phosphine-based curing catalysts such as triphenylphosphine and diphenylphosphine; Examples include imidazoles such as 2-methylimidazole and 2-phenyl-4-methylimidazole.
These can be used alone or in combination of two or more.

Furthermore, thermal curing or photocuring can be achieved by adding a thermal cation curing catalyst or a photo cation curing catalyst.
Examples of the thermal cation curing catalyst include benzylsulfonium salts, thiophenium salts, thiolanium salts, benzylammonium salts, pyridinium salts, hydrazinium salts, carboxylic acid esters, sulfonic acid esters, and amine imides.
These can be used alone or in combination of two or more.
Examples of the photocationic curing catalyst include sulfonium salts and iodonium salts. Examples of sulfonium salts include triphenylsulfonium hexafluorophosphate and triphenylsulfonium hexafluoroantimonate, and examples of iodonium salts include diphenyliodonium tetrakis(pentafluorophenyl)borate and diphenyliodonium. Examples include hexafluorophosphate.
These can be used alone or in combination of two or more.

[(C) Conductive particles]
The anisotropically conductive resin composition of the present invention contains (C) conductive particles as an essential component.
(C) Examples of the conductive particles include metals and carbon. Examples of the metal include transition metals such as nickel (Ni) and copper (Cu); noble metals such as gold (Au), silver (Ag), and platinum group metals; and alloys such as solder.
The conductive particles are preferably coated particles in which core particles are coated with the metal or carbon.
From the viewpoint of easily obtaining a sufficient pot life, the outermost layer of the conductive particles preferably contains a noble metal such as Au, Ag, or a platinum group metal, and more preferably contains Au.
The conductive particles may have, for example, a core made of a transition metal such as Ni, and the surface coated with a noble metal such as Au, or a core made of non-conductive glass, ceramic, plastic, etc., and the surface coated with a noble metal such as Au. The conductive layer of the metal or the like may be formed by coating or the like. The conductive layer may be a single layer or a plurality of layers, but the outermost layer is preferably a noble metal layer.

Coated particles (for example, conductive particles with plastic cores) or heat-melting metal particles can be deformed by heating and pressure, so they can be used to eliminate variations in the height of circuit electrodes, etc. during connection. It is easy to increase the contact area with circuit electrodes and the like, which is thought to further improve reliability.

When the outermost layer of the conductive particles is a noble metal layer, the thickness of the noble metal layer is usually 10 nm or more from the viewpoint of sufficiently reducing the resistance between connected circuits. However, when a noble metal layer is provided on a transition metal such as Ni, for example, when the conductive particles are mixed and dispersed, the noble metal layer may be damaged, and the transition metal such as Ni may be formed in the anisotropically conductive resin composition. Free radicals may be generated due to the oxidation-reduction action of the transition metal, and the free radicals may reduce the storage stability of the anisotropically conductive resin composition. Therefore, the thickness of the noble metal layer is preferably 30 nm or more, more preferably 60 nm or more, and even more preferably 100 nm or more.
The upper limit of the thickness of the noble metal layer is not particularly limited, but from the viewpoint of manufacturing cost, it is usually 1 μm or less.

The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, from the viewpoint of easily responding to variations in the height of the circuit electrodes and preventing the conductivity between the circuit electrodes from decreasing. The average particle diameter of the conductive particles is preferably 10 μm or less, more preferably 5 μm or less, from the viewpoint of preventing the insulation between adjacent circuit electrodes from decreasing. From these viewpoints, the average particle size of the conductive particles is preferably 0.5 to 10 μm, more preferably 1 to 5 μm, and even more preferably 1.5 to 4.5 μm. The average particle diameter of the conductive particles can be measured by observing 100 arbitrary conductive particles with a microscope.

The content of the conductive particles is preferably 0.1 part by mass or more based on 100 parts by mass of the total mass of the anisotropically conductive resin composition from the viewpoint of excellent conductivity. The content of the conductive particles is preferably 50 parts by mass or less, more preferably 40 parts by mass, based on 100 parts by mass of the total mass of the anisotropic conductive resin composition, from the viewpoint of easily suppressing short circuits in adjacent circuits. It is as follows. From these viewpoints, the content of the conductive particles is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 40 parts by mass, based on 100 parts by mass of the total mass of the anisotropically conductive resin composition. Parts by weight, more preferably 0.1 to 30 parts by weight.
The conductive particles are dispersed in the anisotropically conductive composition at a density such that the anisotropically conductive resin composition can function as an anisotropically conductive adhesive after the anisotropically conductive resin composition is pressurized and heated. There is. Specifically, the conductive particles preferably account for 15 to 60%, more preferably 25 to 60%, per horizontal projected area. The number of particles per unit area largely depends on the average particle diameter, but from the viewpoint of conductivity, it is preferably 10,000 to 100,000 particles/mm ² , more preferably 20,000 to 70,000 particles/mm 2 It is more preferably 30,000 to 60,000 pieces/mm ^{2 .}

[(D) Fluorine-containing polymer]
The anisotropically conductive resin composition of the present invention contains (D) a fluoropolymer as an essential component.
In the present invention, the fluorine-containing polymer refers to a polymer compound having a fluorine atom in its molecule.
The fluorine-containing polymer preferably includes a copolymer of a fluoroolefin and a monomer that does not have a fluorine atom.

Examples of the fluoroolefins include fluoroolefins having 2 to 3 carbon atoms, such as tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, hexafluoropropylene, and pentafluoropropylene, or fluoroolefins having 4 or more carbon atoms. can be mentioned. Among these, preferred are tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, and vinylidene fluoride, and more preferred are tetrafluoroethylene and chlorotrifluoroethylene. These fluoroolefins may be used alone or in combination of two or more.

Examples of fluoroolefin homopolymers and copolymers of two or more fluoroolefins include polyvinylidene fluoride, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymers, vinylidene fluoride-chlorotrifluoroethylene-hexafluoro Examples include propylene copolymers.

As the monomer having no fluorine atom, vinyl monomers such as vinyl ether, isopropenyl ether, and carboxylic acid vinyl ester are preferred.

Examples of vinyl ethers include alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, cyclohexyl vinyl ether, tert-butyl vinyl ether, octyl vinyl ether, neopentyl vinyl ether; phenyl vinyl ether, benzyl vinyl ether, naphthyl Aromatic vinyl ethers such as vinyl ether; 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 9-hydroxynonyl vinyl ether, 1-hydroxymethyl-4-vinyloxymethylcyclohexane, 3-chloro-2- Examples include hydroxyalkyl vinyl ethers such as hydroxypropyl vinyl ether.
Among these, alkyl vinyl ethers or hydroxyalkyl vinyl ethers are preferred from the viewpoint of transparency.

Isopropenyl ethers include isopropenyl ethers such as methyl isopropenyl ether, ethyl isopropenyl ether, propyl isopropenyl ether, butyl isopropenyl ether, and cyclohexyl isopropenyl ether; 2-hydroxyethyl isopropenyl ether, 3-hydroxypropyl iso Hydroxyalkyl isopropenyl ethers such as propenyl ether, 4-hydroxybutyl isopropenyl ether, 9-hydroxynonyl isopropenyl ether, 1-hydroxymethyl-4-isopropenyloxymethylcyclohexane, 3-hydroxy-2-chloropropyl isopropenyl ether, etc. Examples include:

Examples of carboxylic acid vinyl esters include vinyl carboxylates such as Beoba-10 (trade name, manufactured by Shell Chemical Co., Ltd.) having a branched alkyl group, vinyl acetate, vinyl butyrate, vinyl pivalate, vinyl benzoate, and vinyl versatate. can be mentioned.
These fluorine-free monomers may be used alone or in combination of two or more.

Other copolymerizable monomers that do not have a fluorine atom include α-olefins such as ethylene, propylene, and isobutylene, and haloolefins such as vinyl chloride and vinylidene chloride (excluding fluoroolefins). ), allyl carboxylates such as allyl formate, allyl butyrate, allyl benzoate, allyl cyclohexanecarboxylate, allyl propionate, allyl ethers such as ethyl allyl ether, cyclohexyl allyl ether, allyl phenyl ether, ethyl acrylate, methacrylic acid Examples include (meth)acrylic esters such as methyl and butyl methacrylate.
These other copolymerizable monomers may be used alone or in combination of two or more. For example, a copolymer containing tetrafluoroethylene, ethylene, or propylene as a main component, or a composite of this copolymer with an acrylic resin component by seed polymerization or the like is preferable.

In the present invention, the fluoropolymer (D) includes a polymerized unit (a) based on a fluoroolefin, a polymerized unit (b) based on an alkyl vinyl ether, and/or a polymerized unit (c) based on a carboxylic acid vinyl ester. , a fluorine-containing copolymer is more preferable.

Further, in one embodiment, for example, the fluorine-containing polymer (D) includes CTFE (chlorotrifluoroethylene), hydroxybutyl vinyl ether, and a monomer copolymerizable with the CTFE and the hydroxybutyl vinyl ether. It is even more preferable.
Examples of the copolymerizable monomer include the aforementioned other copolymerizable monomers that do not have a fluorine atom.
Examples of copolymers of CTFE-based polymers having a curable functional group include "Obrigade" (registered trademark) manufactured by AGC Cortech, "Lumiflon" (registered trademark) manufactured by Asahi Glass Co., Ltd., and "Lumiflon" (registered trademark) manufactured by DIC Corporation. Examples include "Fluonate" (registered trademark) manufactured by Co., Ltd., and "Cepural Coat" (registered trademark) manufactured by Central Glass Co., Ltd.

Further, from the viewpoint of obtaining a suitable film, the number average molecular weight is preferably 2,000 to 100,0000, more preferably 5,000 to 50,000. If the number average molecular weight is less than 2,000, the strength of the film base material may be lowered, and if the number average molecular weight exceeds 100,000, the film forming properties may be poor.

In the present invention, the fluoropolymer is preferably used in an amount of 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, and even more preferably is 12 to 25 parts by mass.

(Other ingredients)
A coupling agent may be added to the anisotropically conductive resin composition of the present invention. The coupling agent is not particularly limited as long as it is a known coupling agent that can be blended into this type of resin composition, and examples thereof include silane coupling agents and titanate coupling agents. Silane coupling agents typically include epoxysilanes, aminosilanes, cationic silanes, vinylsilanes, acrylicsilanes, mercaptosilanes, and composites thereof, and can be used in any desired amount. . In addition, the titanate coupling agent is usually a titanate coupling agent having an alkylate group having at least 1 to 60 carbon atoms, a titanate coupling agent having an alkyl phosphite group, or a titanate cup having an alkyl phosphate group. Examples include a ring agent, a titanate coupling agent having an alkyl pyrophosphate group, and a composite coupling agent thereof, which can be used in any desired amount.
Note that the amount of the coupling agent blended is typically 5% by mass or less based on 100% by mass of the anisotropically conductive resin composition.

Moreover, additives such as an antioxidant, a mold release agent, an ion trapping agent, etc. may be added to the anisotropically conductive resin composition of the present invention, if necessary.

[Method for producing anisotropically conductive adhesive film]
The anisotropic conductive resin composition of the present invention can be manufactured by applying a known method.
For example, the above-mentioned components (A) to (D) and various components to be blended as necessary are mixed using a known kneading machine such as a pot mill, a ball mill, a bead mill, a roll mill, a homogenizer, a super mill, and a Raikai machine. The anisotropically conductive resin composition can be produced by kneading at room temperature or under heating, followed by dilution with a solvent if necessary.
The typical desirable viscosity of the anisotropically conductive resin composition obtained by diluting with a solvent is about 0.5 to 2 Pa·s.

The anisotropically conductive adhesive film of the present invention can be obtained by applying the anisotropically conductive resin composition obtained by diluting it with a solvent onto a support film by a known method and drying it.
Specifically, it is applied onto a support film by a known coating method such as a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, etc., and is dried to a semi-cured state. It can be obtained by The drying temperature may be 70°C to 180°C, or 80°C to 150°C. When the drying temperature is 70°C or higher, the amount of solvent remaining in the sheet is small, and the generation of voids when curing the anisotropically conductive resin composition is suppressed, and when the drying temperature is 150°C or lower, film formability is high, Easier to handle. A specific example of the coating device is μ Coat 350 manufactured by Yasui Seiki Co., Ltd.

[Method for manufacturing micro LED array display device]
The method for manufacturing a micro LED array display device of the present invention includes temporarily attaching the anisotropically conductive adhesive film onto a substrate using a known means such as a roll, and placing the anisotropically conductive adhesive film on a substrate at 70° C. to 180° C., 0.1 to 5 MPa, and 0.1 to 100° C. After fixing for 1 minute, micro LEDs with long sides of 50 to 200 μm and short sides of 10 to 50 μm are mounted at predetermined intervals, and heated and cured at 150 to 200°C, 1 to 10 MPa, and 0.1 to 2 hours. This can be obtained by bonding micro-LEDs in an array to a substrate.
Although not particularly limited, the term array means, for example, that the micro LEDs are arranged in M rows and N columns. However, M and N are integers here, and at least one of M and N is 2 or more.

EXAMPLES Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples in any way.

[Synthesis example 1]
(A) Synthesis of silicone-modified epoxy resin Hydrogenpolydimethylsiloxane [Product name: DMS-H03, Gelest, Inc. ．． 85.0 parts by mass of 100% of toluene and 100 parts of toluene were added, and the mixture was stirred at room temperature. Platinum divinyltetramethyldisiloxane complex xylene solution [trade name: SIP6831.2, Gelest, Inc. 0.075 parts by mass] was added, and the mixture was heated to 60° C. using a mantle heater. 53.1 parts by mass of monoallyl glycidyl isocyanuric acid [trade name: MADGIC, manufactured by Shikoku Kasei Kogyo Co., Ltd.] was added thereto and dissolved. Thereafter, the temperature was raised to 110°C, and the mixture was stirred for 4 hours.
Next, 11.9 parts by mass of liquid polybutadiene [trade name: NISSO PB G-1000, manufactured by Nippon Soda Co., Ltd.] dissolved in 50 parts by mass of toluene was added dropwise to the reaction solution over 30 minutes, and further heated at 110°C for 4 hours. Stir for hours. A silicone-modified epoxy resin was obtained by distilling off the solvent of the obtained reaction mixture under reduced pressure.

[Examples 1 and 2, Comparative Examples 1 to 3]
Each component was mixed at the blending ratio shown in Table 1 to obtain an anisotropically conductive resin composition.
The obtained anisotropically conductive resin composition was applied to a polypropylene film with a thickness of 40 μm using a roll coater so that the thickness after drying was 5 μm, and dried at 80° C. for 1 minute to form an anisotropically conductive resin composition. A adhesive film was obtained.
The obtained anisotropically conductive adhesive film was evaluated by the method described below. The results are also shown in Table 1. The materials used in Examples and Comparative Examples had the following characteristics.

(A) Silicone modified epoxy resin: Synthesis example 1
Other resins/silicone resins (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KER-3000-M2)
・Epoxy resin with isocyanuric acid structure (manufactured by Nissan Chemical Co., Ltd., product name: TEPIC-FL)

(B) Curing agent/(B1) 4-methyl-hexahydrophthalic anhydride (manufactured by Shin Nihon Rika Co., Ltd., trade name: Rikacid MH)
・(B2) Isocyanate curing agent (manufactured by Tosoh Corporation, product name: Coronate HX)

・Curing accelerator: Tetra-n-butylphosphonium-O,O'-diethylphosphorodithionate (manufactured by Nihon Kagaku Kogyo Co., Ltd., trade name: PX-4ET)

(C) Conductive particles/gold-plated resin particles (manufactured by Sekisui Chemical Co., Ltd., product name: Micropearl AU, average particle size: 5 μm)

(D) Fluorine-containing polymer/(D1) Hydroxyl group-containing CTFE copolymer (manufactured by AGC Asahi Glass Co., Ltd., product name: Lumiflon LF-400, hydroxyl value 47 mgKOH/g, acid value 5 mgKOH/g)
・(D2) Hydroxyl group-containing CTFE copolymer (manufactured by AGC Asahi Glass Co., Ltd., product name: Lumiflon LF-552, hydroxyl value 21 mgKOH/g, acid value 1.5 to 2.5 mgKOH/g)

Other ingredients: Silane coupling agent (manufactured by Shin-Etsu Silicone Co., Ltd., product name: KBM-303)

<Evaluation method>
(1) Adhesion After applying an anisotropic conductive adhesive to a printed evaluation board, mounting a 50 μm x 50 μm LED, and bonding by heating at 200°C for 1 hour, use an adhesive strength measuring device (manufactured by Seishin Shoji Co., Ltd.). , model name: SS-30WD) in an environment of 25°C and 260°C, and the rate of change (rate of decrease) in the adhesive strength at 260°C with respect to the adhesive strength at 25°C was calculated. The evaluation criteria are as follows.
[Evaluation criteria]
○: Less than 10% △: 10% or more and less than 20% ×: 20% or more

(2) Initial transmittance 100 sheets of the above anisotropically conductive adhesive film were stacked on a cell made by sandwiching a 0.5 mm thick silicone rubber sheet as a spacer between two glass plates, and the film was heated at 120°C for 2 hours. It was cured by heating at 150° C. for 5 hours to create a plate-shaped cured product with a thickness of 0.5 mm.
Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, product name: V-570), the light transmittance at a wavelength of 460 nm of the plate-shaped cured product after heat curing was measured. The evaluation criteria are as follows.
[Evaluation criteria]
○: 90% or more △: 80% or more and less than 90% ×: less than 80%

(3) Heat resistance test (1)
The heat-cured plate-shaped cured product obtained in (2) above was heat-treated in an atmospheric oven at 150° C. for 24 hours. Further, the light transmittance at 460 nm of the plate-shaped cured product after this heat treatment was measured, and the rate of change was calculated. The evaluation criteria are as follows.
[Evaluation criteria]
○: 90% or more △: 80% or more and less than 90% ×: less than 80%

(4) Heat resistance test (2)
The heat-cured plate-shaped cured product obtained in (2) above was heat-treated in an atmospheric oven at 150° C. for 1000 hours. Further, the light transmittance at 460 nm of the plate-shaped cured product after this heat treatment was measured, and the rate of change was calculated. The evaluation criteria are as follows.
[Evaluation criteria]
○: 90% or more △: 80% or more and less than 90% ×: less than 80%

(5) Light resistance test (1)
The heat-cured plate-shaped cured product obtained in (2) above was heated for 24 hours using a UV irradiation device (manufactured by Oak Seisakusho, product name: UV-300, high-pressure mercury lamp, using a wavelength cut filter of 400 nm or less). Treated with UV irradiation. Further, the light transmittance at 460 nm of the plate-shaped cured product after the irradiation treatment was measured, and the rate of change was calculated. The evaluation criteria are as follows.
[Evaluation criteria]
○: 90% or more △: 80% or more and less than 90% ×: less than 80%

(6) Light resistance test (2)
The heat-cured plate-shaped cured product obtained in (2) above was heated for 1000 hours using a UV irradiation device (manufactured by Oak Seisakusho, product name: UV-300, high-pressure mercury lamp, using a wavelength cut filter of 400 nm or less). Treated with UV irradiation. Next, the light transmittance at 460 nm of the plate-shaped cured product after the irradiation treatment was measured, and the rate of change thereof was calculated. The evaluation criteria are as follows.
[Evaluation criteria]
○: 90% or more △: 80% or more and less than 90% ×: less than 80%

(7) Migration resistance The anisotropically conductive adhesive film obtained in the example was applied to a comb-shaped patterned substrate (substrate material: aluminum nitride, electrode material: Cu, 5 pieces at 0.1 mm intervals) at 200°C and 1 MPa at 60°C. By applying a voltage of 100V to the electrodes for 1000 hours in an environment of 85°C and 85% RH to perform a migration property test on a sample (50 x 50mm, thickness: 0.1mm) that was thermocompressed for 10 minutes, Migration resistance was evaluated. The evaluation criteria are as follows.
[Evaluation criteria]
○: No migration occurs ×: Migration occurs

Examples 1 and 2 in which a silicone-modified epoxy resin and a fluoropolymer were used as resins were compared to Comparative Example 2 in which only an epoxy resin was used (poor light resistance), and Comparative Example 3 in which only a silicone resin was used (poor adhesion). In addition, compared to Comparative Example 1 (poor adhesion) in which only a fluorine-containing polymer was used as the resin, adhesion, light transmittance, heat resistance, light resistance, and migration resistance were improved. You can see that everything is fulfilled at the same time.

Claims (6)

An anisotropically conductive resin composition comprising (A) a silicone-modified epoxy resin, (B) a curing agent, (C) conductive particles, and (D) a fluoropolymer,
The silicone-modified epoxy resin (A) has a structure represented by the following general formula (1),
The fluoropolymer (D) contains a polymerized unit (a) based on a fluoroolefin, a polymerized unit (b) based on an alkyl vinyl ether, and/or a polymerized unit (c) based on a carboxylic acid vinyl ester. is a fluorine copolymer,
Anisotropic conductive resin composition.

[In formula (1), R ¹ each independently represents a monovalent organic group, R ² each independently represents a chain aliphatic hydrocarbon group having 1 to 10 carbon atoms, or a cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms. It represents a group selected from an aliphatic hydrocarbon group and a phenyl group, and Y represents an organic group containing a cyclic ether group. X may be the same or different. a and b are positive numbers, a+b=1 and 0.3≦a<1, and n is 1 to 25. ] 2. The fluorine-containing polymer (D) includes CTFE (chlorotrifluoroethylene), hydroxybutyl vinyl ether, and a monomer copolymerizable with the CTFE and the hydroxybutyl vinyl ether . Anisotropic conductive resin composition. 3. The copolymerizable monomer is at least one selected from α-olefins, haloolefins, allyl carboxylates, allyl ethers, and (meth)acrylic esters. anisotropically conductive resin composition. The anisotropic conductive resin composition according to any one of claims 1 to 3 , wherein the conductive particles (C) have an average particle size of 0.5 to 10 μm. An anisotropically conductive adhesive film obtained by forming the anisotropically conductive resin composition according to any one of claims 1 to 4 into a sheet shape. A micro LED display device comprising micro LEDs arranged and mounted in an array on a substrate using the anisotropically conductive adhesive film according to claim 5 .